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Discussion

We are currently over four years into Solar Cycle 24 and it continues to “underwhelm” and be on a pace that would make it the smallest sunspot cycle since Cycle 14 which peaked in February 1906. There is, however, an active sunspot region that is now rotating to a position that will face the Earth directly in just a few days. In fact, this sunspot region, officially named AR1785, generated an M-class solar flare earlier today, but that should not have an effect on the Earth’s upper atmosphere as it occurred while it was not directly facing the Earth.

Despite this newly emerged active sunspot region, solar activity in general has been rather low this year and this is despite the fact that this particular cycle is approaching the expected solar maximum time period in the middle or latter part of 2013. There is a growing belief that, based on the lack of any substantial spike in sunspot activity, the peak of this cycle may have already happened during the latter part of 2011 - much earlier than originally forecasted. Another theory suggests that there may be a “double-peak” solar maximum for this cycle which would mean there could be a sharp spike in sunspot activity still to come later later this year or in early 2014.

Cycle 24 began after an unusually deep solar minimum that lasted from 2007 to 2009 which included more spotless days on the sun compared to any minimum in almost a century. While a weaker solar cycle does not rule out the threat for strong solar storms, it does suggest that they will occur less often than during the stronger and more active cycles. The increasingly likely outcome for a weak solar cycle continues the recent downward trend in sunspot cycle strength that began over twenty years ago with solar cycle 22. In addition, there are some solar scientists who are already predicting that the next cycle, 25, will be even weaker than the current one. According to some research studies, weak solar cycles with extended lengths may actually have a downward effect on global temperatures in the medium and longer range. Weak solar cycles tend to last longer than the strong ones. There have been historical periods with minimal sunspot activity that lasted for several decades such as from the mid 1600’s to the early 1700’s when the so-called “Maunder Minimum” occurred and this period was quite cold globally.

Another interesting aspect to these solar cycle predictions is that this apparent long-term period of weaker and extended solar cycles looks like it will coincide with a cold phase of the Pacific Ocean (negative Pacific Decadal Oscillation (PDO) index). The Pacific Ocean slipped into a cold phase a few years ago and these longer-term oceanic phases tend to last for two or three decades. Global temperature anomalies have tended to trend downward over the past few years seemingly right after the PDO flipped to a negative (cold) phase. We’ll continue to periodically report on sunspot activity and the oceanic cycles here at “thesiweather.com” and monitor any important changes that may unfold.